BackgroundTo determine relapse rates and associated factors among people who use drugs (PWUDs) attending abstinence-oriented drug treatment clinics in Dhaka, Bangladesh.MethodsA cohort of male and female PWUDs admitted to the 3-month drug detoxification-rehabilitation treatment programmes of three non-governmental organisation-run drug treatment clinics in Dhaka, Bangladesh were interviewed on admission and over the following 5 months, which included the first 2 months after discharge. The study subjects comprised 150 male and 110 female PWUDs who had been taking opiates/opioids, cannabis or other drugs (including sedatives) before admission, had provided informed consent and were aged ≥16 years. Interviews were conducted using semi-structured questionnaires at four time points; on admission, at discharge and at 1 and 2 months after discharge. Relapse rates were assessed by the Kaplan–Meier method. Factors associated with relapse on enrolment and after discharge were determined using the Cox proportional hazards regression model.ResultsA greater proportion of female than male subjects relapsed over the study period (71.9% versus 54.5%, p < 0.01). For men, baseline factors associated with relapse were living with other PWUDs (relative hazard ratio [RHR] = 2.27), living alone (RHR = 2.35) and not having sex with non-commercial partners (RHR = 2.27); whereas for women these were previous history of drug treatment (RHR = 1.94), unstable housing (RHR = 2.44), higher earnings (RHR = 1.89), preferring to smoke heroin (RHR = 3.62) and injecting buprenorphine/pethidine (RHR = 3.00). After discharge, relapse for men was associated with unstable housing (RHR = 2.78), living alone (RHR = 3.69), higher earnings (RHR = 2.48) and buying sex from sex workers (RHR = 2.29). Women’ relapses were associated with not having children to support (RHR = 3.24) and selling sex (RHR = 2.56).ConclusionsThe relapse rate was higher for female PWUDs. For both male and female subjects the findings highlight the importance of stable living conditions. Additionally, female PWUDs need gender-sensitive services and active efforts to refer them for opioid substitution therapy, which should not be restricted only to people who inject drugs.